Method and apparatus for producing envelopes having a closure flap

ABSTRACT

The present invention relates to an apparatus for producing envelopes having a closure flap capable of sealing a plurality of times to the main body of the envelope which comprises a conveyor which is adapted for moving the envelopes one by one from one end to the other end of the apparatus, means operative to open the closure flap as the envelope is being moved along by the conveyor, means to cut an opening in the flap, means for fixing on the envelope a band of material having a glossy surface, the band of material being disposed in a position corresponding to the closed flap opposite the opening, and means for fixing an adhesive tape on the flap over the aperture. The invention also relates to a method for producing envelopes having a closure flap capable of adhering a plurality of times to the main body of the envelope which comprises feeding the envelopes one by one to a conveyor, while the envelopes are moving on the conveyor, blowing a jet of air underneath the flap to lift it, thereafter, causing the flap to revolve until it lays flat open on the conveyor, punching an opening in the opened flap, thereafter further moving the envelope on the conveyor, fixing on the envelope a band of material having a glossy surface, the band of material being disposed in a position corresponding to the closed flap opposite the opening, and fixing an adhesive tape on the flap over the opening, finally, closing the flap against the main body of the envelope and removing the envelopes from the conveyor.

United States Patent [191 Gougeon Sept. 23, 1975 4] METHOD AND APPARATUSFOR PRODUCING ENVELOPES HAVING A CLOSURE FLAP [75] Inventor: RobertGougeon, Montreal, Canada [73] Assignee: International Envelope,Limited,

Montreal, Canada 22 Filed: May 28,1974

211 Appl. No.: 474,139

[52] US. Cl. 93/61 B; 93/1 A; 93/8 WA; 93/61 R; 93/84 FF [51] Int. Cl.B31B 1/90 [58] Field of Search 53/31, 206; 93/61 B, 61 R, 93/61 A, 1 A,8 WA, 84 TW, 84 FF; 24/305 Primary Examiner-Roy Lake AssistantExaminer.lames F. Coan Attorney, Agent, or FirmPaul Marcoux; AlanSwabey; Robert E. Mitchell [57] ABSTRACT The present invention relatesto an apparatus for producing envelopes having a closure flap capable ofsealing a plurality of times to the main body of the envelope whichcomprises a conveyor which is adapted for moving the envelopes one byone from one end to the other end of the apparatus, means operative toopen the closure flap as the envelope is being moved along by theconveyor, means to cut an opening in the flap, means for fixing on theenvelope a band of material having a glossy surface, the band ofmaterial being disposed in a position corresponding to the closed flapopposite the opening, and means for fixing an adhesive tape on the flapover the aperture.

The invention also relates to a method for producing envelopes having aclosure flap capable of adhering a plurality of times to the main bodyof the envelope which comprises feeding the envelopes one by one to aconveyor, while the envelopes are moving on the conveyor, blowing a jetof air underneath the flap to lift it, thereafter, causing the flap torevolve until it lays flat open on the conveyor, punching an opening inthe opened flap, thereafter further moving the envelope on the conveyor,fixing on the envelope a band of material having a glossy surface, theband of material being disposed in a position corresponding to theclosed flap opposite the opening, and fixing an adhesive tape on theflap over the opening, finally, closing the flap against the main bodyof the envelope and removing the envelopes from the conveyor.

23 Claims, 11 Drawing Figures US Patent Sept. 23,1975 shw 1 Of43,906,844

US Patent Sept. 23,1975 Sheet 3 01 4 3,906,844

US Patent Sept. 23,1975 Sheet4 f4 3,906,844-

METHOD AND APPARATUS FOR PRODUCING ENVELOPES HAVING .A CLOSURE FLAPBACKGROUND OF THE INVENTION 1. Field of the invention This inventionrelates to a method and an apparatus for producing envelopes having aclosure flap. More particularly, the invention relates to a device ofthe type which is adapted for producing envelopes having a closure flapcapable of adhering a plurality of times to the main body of theenvelope.

2. Description of the invention There is presently on the market a typeof envelope having a closure flap which may adhere to the main body ofthe envelope and can be pulled away from the envelope after which it canbe caused to adhere again a plurality of times to the envelope withoutlosing its sealing effectiveness. At first, these envelopes were more orless produced manually, Le. a good number of manual steps were involvedin making the opening in the flap and also in applying strips ofadhesive material both on the main body of the envelope andover theopening. The demand for such envelopes is forever increasing and at thesame time, the cost of labor is higher and higher. Consequently, inorder to meet the demand, one must stay away from the manual steps asmuch as possible and the operation to produce these envelopes must beautomated as much as possible. However, due to the complexity ofproducing the opening in the closure flap and in applying strips ofadhesives both on the main body and over the closure flap, it has notbeen possible to this date to rely on an apparatus or a device whichwould enable the production of these envelopes to be carried outautomatically.

SUMMARY The present invention relates to an apparatus for producingenvelopes having a closure flap capable of sealing a plurality of timesto the main body of the envelope which comprises a conveyor which isadapted for moving the envelopes one by one from one end to the otherend of the apparatus, means operative to open the closure flap as theenvelope is being moved along by the conveyor, means to cut an openingin the flap, means for fixing on the envelope a band of material havinga glossy surface, the band of material being disposed in a positioncorresponding to the closed flap opposite the opening, and means forfixing an adhesive tape on the flap over the aperture.

The invention also relates to a method for producing envelopes having aclosure flap capable of adheringa plurality of times to the main body ofthe envelope which comprises feeding the envelopes one by one to aconveyor, while the envelopes are moving on the conveyor, blowing a jetof air underneath the flap to lift it, thereafter, causing the flap torevolve until it lays flat open on the conveyor, punching an opening inthe opened flap, thereafter further moving the envelope on the conveyor,fixing on the envelope a band of material having a glossy surface, theband of material being disposed in a position corresponding to theclosed flap opposite the opening, and fixing an adhesive tape of theflap over the opening, finally, closing the flap against the main bodyof the envelope and removing the envel opes from the conveyor.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings which illustrate theinvention,

FIG. 1 is a perspective view' of an ,envelope produced with theapparatus according to the invention;

FIG. 2 is a schematical side elevation view of an apparatus according tothe invention;

FIG. 3 is a schematical top plan view of the device according to theinvention;

FIG. 4 is a view of the feeding mechanism;

FIG. 5 is a top view of the feed table;

FIG. 6 is a top plan view ofa portion of the conveyor showing theopening of the flap;

FIG. 7 is a view of the cutter taken from the exit end of the apparatus;

FIG. 8 is a side view of the cutter;

FIG. 9 is a perspective view of the cutter showing the means of removinga cut piece of paper from the cutter housing;

FIG. 10 is a top view ofa portion of the conveyor between the cutter andthe exit also showing the tape dispenser;

FIG. 11 is a schematical side view of the top tape dispenser.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, moreparticularly FIGS. 2 and 3, the apparatus according to the inventioncomprises a frame 1 and a motor 3 for operating the movable parts of theapparatus. The main sub-assemblies of the apparatus also comprise a feed5, a control panel 7, a cutting device 9, a tape dispenser 11, and aconveyor 13. These are the main parts of the apparatus and each of theseparts will now be described in detail.

However, before turning to that portion of the description, it ispreferable to describe first of all the envelope which is intended to beproduced using the apparatus illustrated in FIGS. 2 and 13 of thedrawings. The envelope [5 (FIG. 1) which is of standard construction andis preferably of the large type, comprises a closure flap 17 which isshown in the opened position in FIG. 1 of the drawings. The closure flap17 has an opening 19 which in the example illustrated is of ovoidalshape. However, any shape can be used depending on the design andpreference of the producer of the envelope. A band of material 211having a glossy surface has been disposed on the main body of theenvelope in a position corresponding to the closed flap opposite theopening 19. Finally, an adhesive tape 23 has been fixed on the closureflap over the opening 19.

Going back to the envelope 15, before the latter has been formed with anopening 19 and before it has been provided with a band of material 21and adhesive tape 23, it will be realized that for an automaticproduction, the envelopes 15 must be stacked in a pile for the purposeof automatically feeding them into the apparatus. The pile will be shownat 25 in FIG. 4 of the drawings. It will be seen that the pile 25 willbe disposed on a feed table 27 which is slanted at an angle ahead of thefeed mechanism and over which there are provided four paper guides 29which are mounted perpendicularly to the surface of the feed table 27and are all adjustable by means of slotted guide holders 29a and knobs29b to form the corners of a trapeze of various size (see FIG. 5). Thiswill of course all depend on the size of the envelopes which areintended to be fed to the machine.

Having thus disposed the envelopes in a pile 25 in front of theapparatus, the idea is now to feed these envelopes 15 one by one fromthe pile 25 through the apparatus which will taken care of all theoperations. This will be done by the feed mechanism which we will nowdescribe.

The feed mechanism 5 comprises first of all a separator 31 which as willbe seen from FIG. 4 of the drawings is a type of plate with a sharpleading edge 33 to enable the separator 31 to be inserted at the bottomof the pile for the purpose of separating the bottom envelope from theremainder of the pile of envelopes. To operate'in this manner, theseparator 31 is mounted at the end of an arm 35 the latter being coupledto a cam not shown which will serve to oscillate the arm 35 between theposition illustrated in full line in FIG. 4 where the separator 31 isinserted between the bottom envelope and the remainder of the pile andthe position illustrated in dotted lines in FIG. 4 wherein the separator31 has moved out of the pile to be prepared to be reinserted between thenext envelope and the remainder of the pile. The feeding mechanism alsocomprises a suction cup 39 which is connected to a vacuum tube 41. Itwill obviously be realized that the suction cup 39 will serve to gripthe bottom envelope which has been separated from the pile 25 by theseparator 31. The suction applied to the suction cup 39 will cause thefront edge 43 of the bottom envelope to be bent toward the suction cup39. By selecting a suitable timing in the control panel 5, the frontedge 43 of the envelope will be bent in the position illustrated in FIG.4 of the drawings, exactly when the feed disc 45 is in a position toengage the front edge of the envelope 15. To better illustrate thisinvention, we will now describe the remaining portions of the feedmechanism 5 of the apparatus according to the invention. There areprovided two feed discs 45, 47 (FIG. 6) but for the purpose of clarity,we will describe only one of those discs, i.e., disc 45. The feed discs45 and 47 are both rotatable and are each formed with a jaw 51 whichwill serve to engage the bottom envelope. The jaw 51 as shown in FIG. 4of the drawings is rectangular in cross-section. The remaining part ofthe feed mechanism consists of alternate feed rollers 53 and feed rollerspacers 55. This combination of feed rollers 53 and feed roller spacers55 forms a type of support which is arcuately arranged to correspond toan arc portion of the feed discs 45 and 47. It will therefore be seenthat as soon as the envelope has been picked up by the jaws 51, it willbe engaged between the outer periphery of both feed discs 45 and 47 andthe cushion formed by the feed rollers 53 and feed roller spacers 55.The envelope will exit at 57 to be deposited on the conveyor 13 of whichwe will now describe the portion between the feed mechanism 5 and thecutter 9.

The idea is now to take the envelope 15 which has been deposited to lietransversely on the conveyor 13 and while leading it to the cutter 9,previously taking steps to open the closure flap 17 of the envelope 15.Between a location 59 which is immediately at the exit from the feedingmechanism 5 and a position 61 (see FIG. 2) which is intermediate betweenthe feeding mechanism 5 and the cutter 9, the conveyor consists of fourspacedly mounted fabric belts 63, 65, 67 and 69 which run longitudinallyand forwardly of the frame 1. The remaining portion of the conveyor 13consists of four spacedly mounted top plates 71, 73, 75 and 77 which arein the c'ontinuationof the four fabric belts 63, 65, 67 and 69respectively and are also longitudinally mounted with respect to theapparatus and in which their axes correspond to the axes of the fourspacedly mounted fabric belts 63,65, 67 and '69. The spaces formedbetween the four fabric belts 63, 65, 67 and 69 and the four top plates71, 73,75 and 77 are respectively. continuous and define threelongitudinal channels 79, 81 and 83 which extend from one end to theother end of the apparatus. Referring again to the drawings moreparticularly to FIG. 6, it will be seen that lugs 85 which are carriedby corresponding sprocket chains 86 are mounted to travel from one endto the other end of the channels 79, 81 and 83. It will be realized thatthree corresponding lugs 85, 85a, 85b of separate channels 79, 81 and 83must always be perfectly aligned because these lugs will be used to abutthe rear end of the envelope and to feed them from one end to the otherend of the apparatus while lying perfectly transversely relative to theconveyor. The apparatus could also be operable without the use of thefab ric belts 63, 65, 67 and 69, however, it has been found out that theenvelope is much more easily set on the top plates 71, 73, 75 and 77 ifit is first of all engaged at the exit from the feeding mechanism 5 byfabric belts. It should be mentioned at this time that the control box 7should also be set to arrange for the fabric belts to be movable at aspeed lower than the lugs in order to prevent wobbling of the envelopesas they move forward on the conveyor 13. Once wobbling has beenprevented, the task assigned to the fabric belts is over and this is whythe conveyor then can consist only of the top plates 71, 73, 75 and 77.After the envelope has left the fabric belts and now that it is runningover the top plates and it is being moved forward by means of three lugs85, it is necessary, previous to forming the opening 19 in the closureflap 17, to open the closure flap 17.

It will be realized that the envelope 15 is fed to the apparatus withthe closure flap just merely closed. After the envelope has travelledover a certain distance over the conveyor, with the flap closed, but notsealed, it will be understood that the flap will have a natural tendencyto lift even for a very minute amount. In this position reached by theenvelope 15, there is provided a nozzle 87 (see FIG. 6) which isconnected to an air supply under pressure to produce a jet of air 89.This will obviously force the closure flap to lift for a substantialamount. The idea is now to take this substantially lifted closure flapand making it possible for the closure flap 17 to revolve and to layflat open against the top face of the conveyor. This is made possible bythe provision of a flat horizontal bar 91 which as shown is angularlydisposed with respect to the longitudinal axis of the conveyor and isspaced from the top surface of the conveyor to enable the envelope topass underneath it. As illustrated, the bar 91 extends outwardly from alocation near the air jet 89 to a second location 92 before the cutter9. It will be seen that the bar 91 will engage over the closure flapwhich has been substantially lifted by the air jet 89 and as theenvelope will move over the conveyor, the bar will completely open theflap and will cause it to revolve 180 after which the closure flap willlay flat open against the top face of the conveyor. To retain theclosure flap in the flat open position against the top face of theconveyor, there is provided a longitudinal flat covering strip 93 whichis provided in the continuation of the horizontal bar 91 and extendsparallel to the longitudinal axis of the conveyor to a location justimmediately before the envelope reaches the cutter 9. It will berealized that the longitudinal flat covering strip 93will retain theclosure flap l7 flat open against the top surface of the conveyor whilethe envelope travels on the conveyorv until it reaches the cutter 9.

The envelope 15 is now ready to be treated by the cutter 9 to formopening 19 in the closure flap 17.

We will now describe the cutting device 9 illustrated in FIGS. 7, 8 and9. For forming the-opening 19 in the closure flap 17, there is firstprovided a rotatable cutter wheel 95 which is mounted at the end of ashaft 97 and is disposed in such manner on the apparatus that its outerboundary 99 when viewed in the uppermost portion of the cutter wheel 95lies in the same general plane as the top surface. of the conveyor. Thecutting device also comprises a rotatable cutter housing 101 which is ofa generally prismatic shape and is also mounted at the end of a shaft103. The rotatable cutter housing 101 is mounted to rotate above therotatable cutter wheel and is arranged to rotate in a direction which isopposite that of the rotatable cutter wheel 95. The rotatable cutterhousing 101 has an ovoidal cutter 105 mounted on one of its faces in themanner illus trated in FIG. 8 of the drawings. As shown, the cutter 105projects outwardly from that face and it will be seen that upon rotationof the rotatable cutter housing 101, the cutter 105 will be engageablewith the outer boundary 99 of the rotatable cutter wheel 95 to. cut anovoidal opening in the closure flap.

Both shafts 97 and 103 respectively of the cutter wheel 95 and of thecutter housing 101 are operatively connected to the motor 3 in knownmanner. It must, however, be remembered that the cutter wheel and therotatable cutter housing must rotate in opposite direction as indicatedby arrows 107 and 109 in FIG. 8 of the drawings.

Obviously, after having cut the opening 19 in the closure flap 17, thecutter 105 will have removed an ovoidal piece of paper which as a resultof the rotation of the rotatable cutter housing will be received insidethe rotatable cutter housing 101. In order to remove this small ovoidalpiece of paper, the cutter housing is formed with a pair of openings 111and 113. Opposite the cutter housing there is provided a U-shapedtubular member 114 which is connected to a source of air under pressureand which will introduce two jets of air in said the housing. These jetsof air will cause the small ovoidal piece of paper to be removed fromthc cutter housing 101 through the opening 115 where it will be sent toa box not shown through a chute also not shown.

After the opening 19 has been made in the closure flap 17, the envelope15 will obviously continue to cause the closure flap 17 to return to arevolved flat open position against the top face ,of the conveyor 13after which the closure flap will be retained in the same flat openposition while travelling on the conveyor 13 travel on the conveyor 13and for reasons which will be h given hereinafter, the closure flap mustagain be lyingf 'i flat open on the top surface of the conveyor 13. Forthis purpose, there is provided a second bar 117 (see FIG.

9) which extends outwardly from a location immedi-' ately past thecutter I05 and the cutter wheel .95 to a location intermediate thecutter and the tape dispensersub-assembly 11 which-will be definedlater. It will be seen with reference to the drawings in FIGS. 9 and 10that the second horizontal bar 117 will engage over the closure flap 17after the opening 19 has been formed therein, where the closure flap 17will have by means of a second longitudinal flat covering strip 119which is provided in the continuation of the second horizontal bar 117and extends parallel to the longitudinal axis of the conveyor 13 to alocation immediately before the envelope reaches the tape dispensersubassembly 11.

We shall now describe the tape dispenser subassembly 11. Referring toFIG. 11, the sub-assembly comprises a dispenser 121 which is used forsupplying a continuous band of adhesive 123 having a glossy surfacethereon. The sub-assembly also comprises a rotatable applicator wheel125 which is used to receive the glossy surface of the continuous bandof adhesive material 123 against its outer boundary 127. It must beindicated here that the outer boundary must be capable of slidingrelative to the glossy surface of the adhesive ma terial and the reasonfor that will be given later. Of course, proper tension is maintained inthe continuous band of adhesive material 121 by the provisions of smallpulleys 129, 131, 133, 135. These pulleys will adjust in known mannerthe tension in the band of adhesive material. The sub-assembly alsocomprises a rotatable band cutter 137 which is provided with a knife 139and it will be seen with reference to FIG. 11 of the drawings that theaxis of the rotatable band cutter 137 is in the same horizontal plane asthe axis of the applicator wheel 125. The rotatable band cutter 137 willrotate in opposite direction to the applicator wheel 125 and thedirections of both these units 137 and 125 will be indicated by thearrows 14-1 and 143. Obviously, upon rotation of both units 137 and 125,the knife 139 must be capable of engaging the applicator wheel 125 totransversely cut the continuous band of adhesive material 121.

It must be said here that a proper feed control must be exercised in thedispenser 121 to deliver to the rotatable applicator wheel 125 a lengthof continuous band of adhesive material only sufficient to overlap theouter periphery of the opening 19 after which the band is cut by meansof the knife 139. To achieve such results, the rotatable applicator mustbe capable of sliding relative to the continuous band of material.Proper control should be exercised to both the dispenser 121 and thecutter 137 to cause the continuous band of material to advance only anecessary length before transversely cutting the band. The rotatableapplicator is associated with a suction (not shown) which will cause thelength of adhesive material to be retained against the outer periphery127 of the rotatable applicator until the length of adhesive materialmeet the main body of the envelope opposite the opening 19 in the closedposition of the flap.

In order to make sure that the knife 139 is always in proper operatingcondition, the sub-assembly also comprises a rotatable lubricator 147which rotates in the direction of the arrow 149 and contacts the knife139 at each turn.

At the same time as the piece of adhesive material 21 is applied to themain body of the envelope 15 in the position indicated in FIG. 1 of thedrawings, a piece of adhesive 23(FIG. 1) is applied over the closure 19exactly in the same manner as the piece of adhesive 21 is applied on themain body. However, the device for carrying out this operation ismounted at a level below the top surface of the conveyor and is slightlyoffset with respect to the applicator wheel 125 in order to apply thepiece of adhesive 23. For convenience, this portion of the sub-assemblyhas not been illustrated and will not be described it being understoodthat it is identical to the preceding one except that some modificationmust be made for the purpose of mounting it below the surface of theconveyor. It must be said here that although we have shown a tapedispenser for the adhesive material 21 above the conveyor 13 and anothertape dispenser for the piece of adhesive 23 mounted below the level ofthe conveyor 13, it is obvious that both these dispensers can be mountedone after the other above the conveyor. In this case it is onlysufficient to provide a means for closing the flap 17 between the twotape dispensers.

Now that the two pieces of adhesive 21 and 23 have been applied to theenvelope in the manner illustrated in FIG. 1 of the drawings, it onlyremans to close the envelope and to set it aside. For this purpose,there is provided a third horizontal bar 151 (see FIG. which isangularly disposed with respect to the longitudinal axis of the conveyorand is spaced from the top surface of the conveyor to enable theenvelope to pass underneath the bar 151 after the closure flap has beenclosed. For this purpose, the third horizontal bar extends inwardly froma location immediately past the applicator wheels to another location atthe further end of the machine where the envelope will be fed out of theapparatus. It will be seen that the horizontal bar 151 is shaped tofirst of all engage over the flap after the envelope has passed throughthe applicstor wheels and the closure flap has lifted to some extent asa result of its own inherent energy. Having engaged the outer surface ofthe closure flap, the horizontal bar 151 extending inwardly willcompletely close the closure flap as the envelope travels on theconveyor 13. In order to make sure that the envelope is stable over theconveyor 13 there is also provided another horizontal bar 153 which isspaced from bar 151 and merges therewith at 155.

After this operation is over, the envelope will be received in a basket157 at the end of the apparatus.

The operation of the machine is self-explanatory after having read thepreceding description. However, to summarize, it may be said that a pileof envelopes 25 is disposed at one end of the machine, after which theenvelopes are separately fed one by one to the conveyor 13 by means ofthe letter engaging discs 47 and 45. Once on the conveyor which is firstformed of the fabric belts 65, 67, 69, the envelopes will be engaged attheir rear end by the lugs 85, 85a, 85b and will proceed towards theother end of the machine. At one point, a jet of air 89 will startopening of the closure flap l7 and complete opening of the flap will bemade possible by the horizontal bar 91. The closure flap 17 willthereafter remain flat opened in the position indicated in the drawingsby means of the flat covering strip 93. Then the cutter 105 operating inassociation with the cutter wheel 95 will cut the opening 19 in theclosure flap 17. While retaining the closure flap 17 flat open by meansof the bar 117 and flat covering strip 119, the envelope will thenproceed to the tape dispenser sub-assembly where pieces of adhesive 21and 23 will be applied in the position indicated in FIG. 1 of thedrawings. Thereafter, the closure flap will be closed by means of thehorizontal bar 151' and will be fed out of the apparatus in a mannerknown per se towards the basket 1'57. ii

I claim:

1. An apparatus for producing envelopes having a closure flap capable ofadhering a plurality of times to the main body of the envelope whichcomprises:

'a. a conveyor which is adapted for moving said envelopes one by onefrom one end to the other end of said apparatus,

b. means operative to open said closure flap as said envelope is beingmoved along by said conveyor,

c. means to cut an opening in said flap,

d. means for fixing on said envelope a band of material having a glossysurface, said band of material being disposed in a positioncorresponding to the closed flap opposite said opening, and,

e. means for fixing an adhesive tape on said flap over the saidaperture. 4

2. An apparatus according to claim 1, which further comprises:

f. means to close said flap in engagement over said band of material.

3. An apparatus according to claim 2, which comprises means forsimultaneously carrying out fixing of said band of material and of saidadhesive tape while said flap is open after which said flap is closedand said envelope is moved towards said other end of said apparatus tobe stored away.

4. An apparatus according to claim 2, which is so constructed andarranged that fixing of said band of material is first carried out, thensaid flap is closed, after which said adhesive tape is applied on saidopenmg. I

5. An apparatus according to claim 1, wherein said conveyor comprisesspacedly mounted longitudinal top plates and lugs which are disposedbetween said top plates and project above the surface of said top plate,said lugs being longitudinally movable in the spaces be.- tween said topplates.

6. An apparatus according to claim 5 which comprises four spacedlymounted said top plates defining three longitudinal channels in whichsaid lugs are adapted move.

7. An apparatus according to claim 6, which comprises sprocket chains tocarry said lugs said chains being engaged by corresponding roller chainsprockets, said roller chain sprockets operatively connected to a motor.

8. An apparatus according to claim 7, wherein a first shorter portion ofsaid conveyor consists of fabric belts which are movable at a speedslower than said lugs to prevent wobbling of said envelopes as they moveforward on said conveyor, said conveyor thereafter consisting of saidtop plates.

9. An apparatus according to claim 1, wherein said means operative toopen said closure flap comprises a jet of air and means for projectingsaid jet of air underneath said flap thus causing lifting of said flap,said apparatus also including means for keeping said flap continuouslyopened when said opening is cut in said flap, said band of materialhaving a glossy surface is fixed on said envelope in a positioncorresponding to the closed flapopposite said opening and said adhesivetape is fixed on said flap over said aperture.

10. An apparatus accordingto claim 1, which comprises: a v 1 M g. meansfor individually feeding 'said envelopesto said conveyor. j v, t, l

1 1. An apparatus according tocl aim 10, which cornprises means forstacking envelopes in a pile in front of said means for individuallyfeeding said envelopes to said conveyor, means for 'grip ping'the bottomenvelope from said pile and bringing the same forward toward saidconveyor and letter engaging feed disc means adapted to engage saidbottom envelope and means associated with saidfeed disc means uponrotation of the latter to carry said bottom envelope to said conveyor.

12. An apparatus according to claim 11, which comprises a separatorwhich is insertable at the bottom of said pile of envelopes to separatethe bottom envelope from the remainder of the pile of envelopes, saidseparator mounted at the end of an arm and a cam to actuate said arm andto cause said separator to separate said bottom envelope at eachrotation of said feed disc means.

13. An apparatus according to claim 12, which comprises a suction cupoperatively connected to a vacuum device to grip said bottom envelopewhich has been separated from said pile by said separator and to bendits front edge toward said feed disc means, after which said envelope isengaged by said feed disc means to be forwarded to said conveyor.

14. An apparatus according to claim 13 wherein said feed disc meanscomprise a pair of rotatable discs each formed with ajaw to engage saidbottom envelope, and alternate feed rollers and feed roller spacersarcuately arranged to enable said bottom envelope to be engaged betweensaid discs and said alternate feed rollers and said feed roller spacersand to thereafter be forwarded toward said conveyor.

15. An apparatus according to claim 9, which comprises a firsthorizontal bar which is angularly disposed with respect to thelongitudinal axis of said conveyor and is spaced from the top surfacethereof to enable said envelope to pass underneath said first horizontalbar, said first bar extending outwardly from a first location near saidjet of air to a second location before said means to out said opening,said bar engaging over said closure flap after the same has been liftedby said jet of air to completely open said flap and to cause the same torevolve 180 and to lay flat open against the top face of said conveyor,and a first longitudinal flat covering strip provided in thecontinuation of said first horizon tal bar and extending parallel to thelongitudinal axis of said conveyor to a third location immediatelybefore said envelope reaches said means to out said opening in saidflap, said first longitudinal flat covering strip to retain said closureflap flat open against the top of said conveyor, while said envelopetravels on said conveyor between said third location and said means tocut said opening in said flap.

16. An apparatus according to claim 15, wherein said means to cut saidopening in said flap comprise a rotatable cutter wheel in which theouter boundary lies in the same plane as the top surface of saidconveyor, a rotatable cutter housing mounted above said rotatable cutterwheel and arranged to rotate in a direction which is opposite that ofsaid rotatable cutter wheel, said rotatable cutter housing having acutter mounted thereon and projecting outwardly therefrom, said cutterengageable upon rotation of said cutter housing with said outer boundaryoffsaid rotatable cutter wheel to out said opening in said closure flap,and means to cause rotation of'said rotatable cutter housing and of saidrotatable cutter wheel;

prises a second horizontal bar which is angularly disl posed withrespect to the longitudinal axis of said conveyor and is spaced fromthetop surface thereof to enable said envelope to pass underneathsaidsecond horizontalbar, said second bar extending outwardly from a fourthlocation past said cutter and said cutter wheel to a fifth locationintermediate said cutter and said means for fixing on said envelope aband of material having a glossy surface, said second horizontal barengaging over said closure flap after an opening has been cut thereinand said closure flap has been slightly lifted by its own inherentenergy, said second horizontal bar to cause said closure flap to returnto said revolved flat open position against the top face of saidconveyor after which said closure flap is retained in said flat openposition while travelling on said conveyor by means of a secondlogitudinal flat covering strip provided in the continuation of saidsecond horizontal bar and extending parallel to the longitudinal axis ofsaid conveyor to a fifth location immediately before said envelopereaches said means for fixing on said envelope a band ofmaterial havinga glossy surface.

18. An apparatus according to claim 17 wherein said means for fixing onsaid envelope a band of material having a glossy surface comprise adispenser for a continuous band of adhesive material having a glossysurface, a rotatable applicator wheel to receive the glossy surface ofthe continuous band of adhesive material against its outer boundary,said outer boundary capable of sliding relative to said glossy surface arotatable band cutter in which the axis is in the same horizontal planeas the axis of the applicator wheel, said rotatable band cutter adaptedto rotate in opposite direction to said applicator wheel and to beengaged therewith, to transversely out said continuous band of adhesivematerial, feed control means delivering to said rotatable applicatorwheel a length of said continuous band of adhesive only sufficient tooverlap the outer periphery of said opening, whereby upon rotation ofsaid rotatable applicator said length of said continuous band ofadhesive will be applied on said main body of said envelope oppositesaid opening in the closed position of said flap.

19. An apparatus according to claim 18, which comprises suction meansassociated with said applicator wheel to retain said piece in adheringcontact with said applicator wheel until said piece is applied on saidmain body.

20. An apparatus according to claim 19, which comprises a rotatablelubricator which is engageable upon rotation with said band cutter tolubricate the same.

21. An apparatus according to claim 20, wherein said means for fixingsaid adhesive tape on said flap over said aperture is identical to saidmeans for fixing on said envelope a band of material having a glossysurface except that it is mounted at a level below said top surface ofsaid conveyor and is arranged to affix a piece of adhesive tape oversaid opening.

22. An apparatus according to claim 21, which comprises a thirdhorizontal bar which is angularly disposed with respect to thelongitudinal axis of said conveyor and is spaced from the top surfacethereof to enable said envelope to pass underneath said third horizontalbar after said closure flap has been closed, said third horizontal barextending inwardly from a sixth location past said applicator wheels toa seventh location where said envelope is fed out of said apparatus,said third horizontal bar shaped to engage over said flap after saidenvelope has passed said applicator wheels, to fold said flap over saidmain body.

23. A method for producing envelopes having a closure flap capable ofadhering a plurality of times to the main body of the envelope whichcomprises feeding the envelopes one by one to a conveyor, while theenvelopes are moving on the conveyor, blowing a jet of air fixing anadhesive tape on the flap over the opening, fi-

nally, closing the flap against the main body of the envelope andremoving the envelopes from the conveyor.

1. An apparatus for producing envelopes having a closure flap capable ofadhering a plurality of times to the main body of the envelope whichcomprises: a. a conveyor which is adapted for moving said envelopes oneby one from one end to the other end of said apparatus, b. meansoperative to open said closure flap as said envelope is being movedalong by said conveyor, c. means to cut an opening in said flap, d.means for fixing on said envelope a band of material having a glossysurface, said band of material being disposed in a positioncorresponding to the closed flap opposite said opening, and, e. meansfor fixing an adhesive tape on said flap over the said aperture.
 2. Anapparatus according to claim 1, which further comprises: f. means toclose said flap in engagement over said band of material.
 3. Anapparatus according to claim 2, which comprises means for simultaneouslycarrying out fixing of said band of material and of said adhesive tapewhile said flap is open after which said flap is closed and saidenvelope is moved towards said other end of said apparatus to be storedaway.
 4. An apparatus according to claim 2, which is so constructed andarranged that fixing of said band of material is first carried out, thensaid flap is closed, after which said adhesive tape is applied on saidoPening.
 5. An apparatus according to claim 1, wherein said conveyorcomprises spacedly mounted longitudinal top plates and lugs which aredisposed between said top plates and project above the surface of saidtop plate, said lugs being longitudinally movable in the spaces betweensaid top plates.
 6. An apparatus according to claim 5 which comprisesfour spacedly mounted said top plates defining three longitudinalchannels in which said lugs are adapted move.
 7. An apparatus accordingto claim 6, which comprises sprocket chains to carry said lugs saidchains being engaged by corresponding roller chain sprockets, saidroller chain sprockets operatively connected to a motor.
 8. An apparatusaccording to claim 7, wherein a first shorter portion of said conveyorconsists of fabric belts which are movable at a speed slower than saidlugs to prevent wobbling of said envelopes as they move forward on saidconveyor, said conveyor thereafter consisting of said top plates.
 9. Anapparatus according to claim 1, wherein said means operative to opensaid closure flap comprises a jet of air and means for projecting saidjet of air underneath said flap thus causing lifting of said flap, saidapparatus also including means for keeping said flap continuously openedwhen said opening is cut in said flap, said band of material having aglossy surface is fixed on said envelope in a position corresponding tothe closed flap opposite said opening and said adhesive tape is fixed onsaid flap over said aperture.
 10. An apparatus according to claim 1,which comprises: g. means for individually feeding said envelopes tosaid conveyor.
 11. An apparatus according to claim 10, which comprisesmeans for stacking envelopes in a pile in front of said means forindividually feeding said envelopes to said conveyor, means for grippingthe bottom envelope from said pile and bringing the same forward towardsaid conveyor and letter engaging feed disc means adapted to engage saidbottom envelope and means associated with said feed disc means uponrotation of the latter to carry said bottom envelope to said conveyor.12. An apparatus according to claim 11, which comprises a separatorwhich is insertable at the bottom of said pile of envelopes to separatethe bottom envelope from the remainder of the pile of envelopes, saidseparator mounted at the end of an arm and a cam to actuate said arm andto cause said separator to separate said bottom envelope at eachrotation of said feed disc means.
 13. An apparatus according to claim12, which comprises a suction cup operatively connected to a vacuumdevice to grip said bottom envelope which has been separated from saidpile by said separator and to bend its front edge toward said feed discmeans, after which said envelope is engaged by said feed disc means tobe forwarded to said conveyor.
 14. An apparatus according to claim 13wherein said feed disc means comprise a pair of rotatable discs eachformed with a jaw to engage said bottom envelope, and alternate feedrollers and feed roller spacers arcuately arranged to enable said bottomenvelope to be engaged between said discs and said alternate feedrollers and said feed roller spacers and to thereafter be forwardedtoward said conveyor.
 15. An apparatus according to claim 9, whichcomprises a first horizontal bar which is angularly disposed withrespect to the longitudinal axis of said conveyor and is spaced from thetop surface thereof to enable said envelope to pass underneath saidfirst horizontal bar, said first bar extending outwardly from a firstlocation near said jet of air to a second location before said means tocut said opening, said bar engaging over said closure flap after thesame has been lifted by said jet of air to completely open said flap andto cause the same to revolve 180* and to lay flat open against the topface of said conveyor, and a first longitudinal flat covering stripprovided in the continuation of said first hoRizontal bar and extendingparallel to the longitudinal axis of said conveyor to a third locationimmediately before said envelope reaches said means to cut said openingin said flap, said first longitudinal flat covering strip to retain saidclosure flap flat open against the top of said conveyor, while saidenvelope travels on said conveyor between said third location and saidmeans to cut said opening in said flap.
 16. An apparatus according toclaim 15, wherein said means to cut said opening in said flap comprise arotatable cutter wheel in which the outer boundary lies in the sameplane as the top surface of said conveyor, a rotatable cutter housingmounted above said rotatable cutter wheel and arranged to rotate in adirection which is opposite that of said rotatable cutter wheel, saidrotatable cutter housing having a cutter mounted thereon and projectingoutwardly therefrom, said cutter engageable upon rotation of said cutterhousing with said outer boundary of said rotatable cutter wheel to cutsaid opening in said closure flap, and means to cause rotation of saidrotatable cutter housing and of said rotatable cutter wheel.
 17. Anapparatus according to claim 16, which comprises a second horizontal barwhich is angularly disposed with respect to the longitudinal axis ofsaid conveyor and is spaced from the top surface thereof to enable saidenvelope to pass underneath said second horizontal bar, said second barextending outwardly from a fourth location past said cutter and saidcutter wheel to a fifth location intermediate said cutter and said meansfor fixing on said envelope a band of material having a glossy surface,said second horizontal bar engaging over said closure flap after anopening has been cut therein and said closure flap has been slightlylifted by its own inherent energy, said second horizontal bar to causesaid closure flap to return to said revolved flat open position againstthe top face of said conveyor after which said closure flap is retainedin said flat open position while travelling on said conveyor by means ofa second logitudinal flat covering strip provided in the continuation ofsaid second horizontal bar and extending parallel to the longitudinalaxis of said conveyor to a fifth location immediately before saidenvelope reaches said means for fixing on said envelope a band ofmaterial having a glossy surface.
 18. An apparatus according to claim 17wherein said means for fixing on said envelope a band of material havinga glossy surface comprise a dispenser for a continuous band of adhesivematerial having a glossy surface, a rotatable applicator wheel toreceive the glossy surface of the continuous band of adhesive materialagainst its outer boundary, said outer boundary capable of slidingrelative to said glossy surface a rotatable band cutter in which theaxis is in the same horizontal plane as the axis of the applicatorwheel, said rotatable band cutter adapted to rotate in oppositedirection to said applicator wheel and to be engaged therewith, totransversely cut said continuous band of adhesive material, feed controlmeans delivering to said rotatable applicator wheel a length of saidcontinuous band of adhesive only sufficient to overlap the outerperiphery of said opening, whereby upon rotation of said rotatableapplicator said length of said continuous band of adhesive will beapplied on said main body of said envelope opposite said opening in theclosed position of said flap.
 19. An apparatus according to claim 18,which comprises suction means associated with said applicator wheel toretain said piece in adhering contact with said applicator wheel untilsaid piece is applied on said main body.
 20. An apparatus according toclaim 19, which comprises a rotatable lubricator which is engageableupon rotation with said band cutter to lubricate the same.
 21. Anapparatus according to claim 20, wherein said means for fixing saidadhesive tape on said flap over said aperture is identical to said meanSfor fixing on said envelope a band of material having a glossy surfaceexcept that it is mounted at a level below said top surface of saidconveyor and is arranged to affix a piece of adhesive tape over saidopening.
 22. An apparatus according to claim 21, which comprises a thirdhorizontal bar which is angularly disposed with respect to thelongitudinal axis of said conveyor and is spaced from the top surfacethereof to enable said envelope to pass underneath said third horizontalbar after said closure flap has been closed, said third horizontal barextending inwardly from a sixth location past said applicator wheels toa seventh location where said envelope is fed out of said apparatus,said third horizontal bar shaped to engage over said flap after saidenvelope has passed said applicator wheels, to fold said flap over saidmain body.
 23. A method for producing envelopes having a closure flapcapable of adhering a plurality of times to the main body of theenvelope which comprises feeding the envelopes one by one to a conveyor,while the envelopes are moving on the conveyor, blowing a jet of airunderneath the flap to lift it, thereafter, causing the flap to revolveuntil it lays flat open on the conveyor, punching an opening in theopened flap, thereafter further moving the envelope on the conveyor,fixing on the envelope a band of material having a glossy surface, theband of material being disposed in a position corresponding to theclosed flap opposite the opening, and fixing an adhesive tape on theflap over the opening, finally, closing the flap against the main bodyof the envelope and removing the envelopes from the conveyor.